thirty[ˈθɜ:ti]的y發/i/音。
He lived in Canada in the thirties.
三十年代他住在加拿大。By sunset we had covered thirty miles.
到日落時我們已走了三十英里。
Some thirty people attended the funeral.
大約有三十人蔘加了葬禮。
She thinks nothing of walking thirty miles a day.
她認為一天步行三十英里不足為奇。
She's in her mid-thirties—thirty-six to be exact.
她三十五歲左右—確切地説是三十六歲。